If that really is the case I'm okay with that. Seeing the needle rest right on 80 degrees every time i glance at it simply makes me happy. I didnt do the thermo change to treat the overheating problem, but just for overall benefit. This is something I have done on several of my cars (this is also a common practice among f-body owners). I have been told by "qualified technicians" that the reason mercedes and many other auto makers engines run as hot as they do is for emissions purposes. Dont get me wrong. There are a lot of cars that you absolutely should not do this on and they can respond very negatively, but the m103 motor seems to like it. It makes me happy and I think it could make other w124 owners out there happy as well. Dont knock it till you try it.
And in response to augapfel, I am pretty much totally positive that a higher operating temperature does not mean a more efficient engine, a cleaner burning engine, yes, but more efficient, no. Otherwise there would be no intercoolers on turbocharged cars and the guys at the drag strip wouldnt be ceramic coating their headers.